test: 修改 Demo15 中的打印函数

playground/Demo/Demo15/Main.snow

@@ -1,13 +1,20 @@
 module: Main
     import: os
     globals:
-        declare num1:int=10
         declare num2:int=10
     function: main
         return_type: void
         body:
             declare num1:int=11
-            print(num1+num2)
+            os.print(num1+num2+abc())
         end body
     end function
+
+    function: abc
+        return_type: int
+        body:
+            return 1
+        end body
+    end function
+
 end module